When materials are transported by a pipe or other duct, such as within industrial facilities and HVAC systems, it is often desirable for the pipe to be insulated. Typically, such insulation is provided by wrapping a layer of insulation around an exterior surface of the pipe. Often this insulation is made from a material which exhibits degraded performance if exposed directly to the weather or other atmospheric conditions surrounding the pipe. In other instances, the insulation does not have a particularly desirable appearance, or is prone to falling off. Insulation cladding is utilized to cover an exterior surface of the insulation surrounding the pipe so that the insulation is held, protected and hidden from view by the cladding.
Such insulation cladding is typically formed from thin sheets of sheet metal (often formed of aluminum or stainless steel) shaped to cover the insulation and riveted together or otherwise fastened to encapsulate the insulation therein. Such insulation cladding thus provides both a decorative function while also protecting the insulation from damage.
One difficulty encountered while installing such cladding involves properly installing cladding surrounding insulation at a bend in the pipe. At such bends, it is desirable to have the cladding curve with the insulation surrounding the pipe. The cladding must thus take on a complex geometric shape generally in the form of a cylinder with a central axis thereof bent about a bend radius of curvature. The cladding must be generally cylindrical, but with a curvature following this bent central axis. Hence, an outside portion of the bend is significantly longer than an inside portion of the bend.
One prior art technique commonly used by sheet metal contractors to install cladding around a bend involves the painstaking custom construction of a bend cladding structure on-site from separate strips of cladding material. These separate strips, often referred to as gores, are sized and shaped to circumscribe the central axis of the bend. These gores thus have an elongate form with a length between ends thereof similar to a circumference of the bend surrounding the central axis.
Each gore has a tapering width with portions of the gore having a small width corresponding with an inside of the bend and with portions of the gore having a larger width corresponding with an outside of the bend. Typically, each gore will have a similar size and geometry. After the gores have been formed, they can be crimped to take on a curved form, or merely be wrapped around the bend. Each of the gores are wrapped around the bend in sequence and fastened to adjacent gores so that the bend is built from one end of the bend to the other end of the bend.
This process of custom manufacturing the cladding from multiple separate gores requires the sheet metal subcontractor to have all of the necessary sheet metal cutting and shaping equipment at the installation site and involves the complex and time consuming procedures associated with such custom manufacture, thus delaying the time associated with the cladding process. The time and difficulty associated with this project is magnified when, as is typically the case, multiple bends are involved which each require appropriate cladding.
A second prior art technique for cladding bends involves the use of prefabricated pressed half bends. A sheet metal press is provided including upper and lower dies with multiple different standard sizes. When the dies are pressed together, the sheet metal therebetween is pressed into the shape that the cladding must take to cover one half of the bend of a particular size and shape bend of insulation. Two identical pressed half bends can then be mated together to form the completed cladding for the particular bend involved. Such pressed half bends typically terminate at seams which are configured to include an inside seam corresponding with the inner radius of curvature of the bend and an outside seam corresponding with an outer radius of curvature of the bend. Thus, the two pressed half bends of identical form each cover the symmetrical opposite sides of the bend. During installation the two halves are riveted together to form the completed structure.
Utilization of such pressed half bends involves numerous drawbacks. Such pressed half bends are limited to particular diameter sizes surrounding the central axis, and particular radii of curvature of the central axis through the bend. Also, an angular form of the bend (i.e. 30°, 45°, 90°, etc.) further increases the number of bend shapes and sizes which must be accommodated by such pressed halves. As each particular shape and size requires a separate press with separate upper and lower dies, such pressed halves have not been able to accommodate all of the different geometries and sizes which exist and require appropriate cladding.
Also, for particularly large bends and for many geometries, the nature of the curve is not well suited to pressing planar sheet metal into a half bend without damaging the sheet metal during the pressing process or involving unacceptably complex press and die configurations. Finally, the pressed half bends have a significantly different appearance from that associated with forming the bends from multiple separate pieces of cladding material. In many installations where appearance is a consideration, the pressed half bends have an undesirable appearance.
Accordingly, a need exists for providing insulation cladding for bends in a way that provides for quick installation, ease of use and desirable appearance for the cladding surrounding the bends. Such cladding should be readily installed on-site, with a minimal amount of skill, effort, time and tools required at the installation site.